It's practically a gift: Obama worked futilely as a "community organizer" in urban Chicago, but insists on keeping DC city schoolkids firmly within the purview of the AFT and NEA (I won't use the incendiary word "plantation", as somehave). Romney can make the easy case that markets and vouchers provide better opportunities for those too poor to leave failing school districts.

While focusing on the poor is good politics, voucher programs shouldn't be means-tested. Why did white flight occur? Why is the gentrification of America's beautiful urban neighborhoods limited to young professionals, gays, dinks, and a handful of over-50 types? Poor schools, of course. In Jamaica Plain, one of the most vibrant and diverse neighborhoods in America, one rarely sees a white person between the ages of 5 and 18, despite a 50% white population.

Those well-off enough to flee the city may not need vouchers as badly as poor students do, but the city needs them. With school choice, neighborhoods can become diverse, as highly-educated urbanites stay in their homes when their eldest kid hits age 4 instead of fleeing to the suburbs or exurbs. Cities rife with boarded-up homes could experience much-needed private investment along with rising tax revenues and greater diversity of achievement. More affluent kids would grow up in poor neighborhoods and be attuned to the breadth of human need. And the taxes paid by well-off parents would allow cities to keep tax rates reasonable, instead of chasing businesses out to the suburbs with a vicious cycle of rising taxes and shrinking tax base.

Does that mean government should take voucher money away from poor kids? Nope - cities and states can expand their voucher programs almost limitlessly, since vouchers are cheaper than keeping kids in the old monopolistic public schools.